Properly convert objects between different ELF classes

The output SHF_COMPRESSED section size is different from input if
ELF classes of input and output aren't the same.  We must adjust
the section sizes as well as the compression headers in
SHF_COMPRESSED sections when converting objects between different
ELF classes.

bfd/

	 PR binutils/18656
	 * bfd.c (bfd_convert_section_size): New function.
	 (bfd_convert_section_contents): Likewise.
	 * bfd-in2.h: Regenerated.

binutils/

2015-07-10  H.J. Lu  <hongjiu.lu@intel.com>

	 PR binutils/18656
	 * objcopy.c (setup_section): Call bfd_convert_section_size
	 to get the output section size.
	 (copy_section): Get the section size from the output section
	 and call bfd_get_full_section_contents to convert section
	 contents for output.

binutils/testsuite/

	 PR binutils/18656
	 * binutils-all/compress.exp (convert_test): New proc.
	 Run conversion tests between x86-64 and x32.

1 files changed, 155 insertions, 0 deletions

diff --git a/bfd/bfd.c b/bfd/bfd.c
index 8d85de5..846ab58 100644
--- a/bfd/bfd.c
+++ b/bfd/bfd.c
@@ -2111,3 +2111,158 @@ bfd_get_compression_header_size (bfd *abfd, asection *sec)
 
   return 0;
 }
+
+/*
+FUNCTION
+	bfd_convert_section_size
+
+SYNOPSIS
+	bfd_size_type bfd_convert_section_size
+	  (bfd *ibfd, asection *isec, bfd *obfd, bfd_size_type size);
+
+DESCRIPTION
+	Convert the size @var{size} of the section @var{isec} in input
+	BFD @var{ibfd} to the section size in output BFD @var{obfd}.
+*/
+
+bfd_size_type
+bfd_convert_section_size (bfd *ibfd, sec_ptr isec, bfd *obfd,
+			  bfd_size_type size)
+{
+  bfd_size_type hdr_size;
+
+  /* Do nothing if input file will be decompressed.  */
+  if ((ibfd->flags & BFD_DECOMPRESS))
+    return size;
+
+  /* Do nothing if either input or output aren't ELF.  */
+  if (bfd_get_flavour (ibfd) != bfd_target_elf_flavour
+      || bfd_get_flavour (obfd) != bfd_target_elf_flavour)
+    return size;
+
+  /* Do nothing if ELF classes of input and output are the same. */
+  if (get_elf_backend_data (ibfd)->s->elfclass
+      == get_elf_backend_data (obfd)->s->elfclass)
+    return size;
+
+  /* Do nothing if the input section isn't a SHF_COMPRESSED section. */
+  hdr_size = bfd_get_compression_header_size (ibfd, isec);
+  if (hdr_size == 0)
+    return size;
+
+  /* Adjust the size of the output SHF_COMPRESSED section.  */
+  if (hdr_size == sizeof (Elf32_External_Chdr))
+    return (size - sizeof (Elf32_External_Chdr)
+	    + sizeof (Elf64_External_Chdr));
+  else
+    return (size - sizeof (Elf64_External_Chdr)
+	    + sizeof (Elf32_External_Chdr));
+}
+
+/*
+FUNCTION
+	bfd_convert_section_contents
+
+SYNOPSIS
+	bfd_boolean bfd_convert_section_contents
+	  (bfd *ibfd, asection *isec, bfd *obfd, bfd_byte **ptr);
+
+DESCRIPTION
+	Convert the contents, stored in @var{*ptr}, of the section
+	@var{isec} in input BFD @var{ibfd} to output BFD @var{obfd}
+	if needed.  The original buffer pointed to by @var{*ptr} may
+	be freed and @var{*ptr} is returned with memory malloc'd by this
+	function.
+*/
+
+bfd_boolean
+bfd_convert_section_contents (bfd *ibfd, sec_ptr isec, bfd *obfd,
+			      bfd_byte **ptr)
+{
+  bfd_byte *contents;
+  bfd_size_type ihdr_size, ohdr_size, size;
+  Elf_Internal_Chdr chdr;
+  bfd_boolean use_memmove;
+
+  /* Do nothing if input file will be decompressed.  */
+  if ((ibfd->flags & BFD_DECOMPRESS))
+    return TRUE;
+
+  /* Do nothing if either input or output aren't ELF.  */
+  if (bfd_get_flavour (ibfd) != bfd_target_elf_flavour
+      || bfd_get_flavour (obfd) != bfd_target_elf_flavour)
+    return TRUE;
+
+  /* Do nothing if ELF classes of input and output are the same. */
+  if (get_elf_backend_data (ibfd)->s->elfclass
+      == get_elf_backend_data (obfd)->s->elfclass)
+    return TRUE;
+
+  /* Do nothing if the input section isn't a SHF_COMPRESSED section. */
+  ihdr_size = bfd_get_compression_header_size (ibfd, isec);
+  if (ihdr_size == 0)
+    return TRUE;
+
+  contents = *ptr;
+
+  /* Convert the contents of the input SHF_COMPRESSED section to
+     output.  Get the input compression header and the size of the
+     output compression header.  */
+  if (ihdr_size == sizeof (Elf32_External_Chdr))
+    {
+      Elf32_External_Chdr *echdr = (Elf32_External_Chdr *) contents;
+      chdr.ch_type = bfd_get_32 (ibfd, &echdr->ch_type);
+      chdr.ch_size = bfd_get_32 (ibfd, &echdr->ch_size);
+      chdr.ch_addralign = bfd_get_32 (ibfd, &echdr->ch_addralign);
+
+      ohdr_size = sizeof (Elf64_External_Chdr);
+
+      use_memmove = FALSE;
+    }
+  else
+    {
+      Elf64_External_Chdr *echdr = (Elf64_External_Chdr *) contents;
+      chdr.ch_type = bfd_get_64 (ibfd, &echdr->ch_type);
+      chdr.ch_size = bfd_get_64 (ibfd, &echdr->ch_size);
+      chdr.ch_addralign = bfd_get_64 (ibfd, &echdr->ch_addralign);
+
+      ohdr_size = sizeof (Elf32_External_Chdr);
+      use_memmove = TRUE;
+    }
+
+  size = bfd_get_section_size (isec) - ihdr_size + ohdr_size;
+  if (!use_memmove)
+    {
+      contents = (bfd_byte *) bfd_malloc (size);
+      if (contents == NULL)
+	return FALSE;
+    }
+
+  /* Write out the output compression header.  */
+  if (ohdr_size == sizeof (Elf32_External_Chdr))
+    {
+      Elf32_External_Chdr *echdr = (Elf32_External_Chdr *) contents;
+      bfd_put_32 (obfd, ELFCOMPRESS_ZLIB, &echdr->ch_type);
+      bfd_put_32 (obfd, chdr.ch_size, &echdr->ch_size);
+      bfd_put_32 (obfd, chdr.ch_addralign, &echdr->ch_addralign);
+    }
+  else
+    {
+      Elf64_External_Chdr *echdr = (Elf64_External_Chdr *) contents;
+      bfd_put_64 (obfd, ELFCOMPRESS_ZLIB, &echdr->ch_type);
+      bfd_put_64 (obfd, chdr.ch_size, &echdr->ch_size);
+      bfd_put_64 (obfd, chdr.ch_addralign, &echdr->ch_addralign);
+    }
+
+  /* Copy the compressed contents.  */
+  if (use_memmove)
+    memmove (contents + ohdr_size, *ptr + ihdr_size, size - ohdr_size);
+  else
+    {
+      memcpy (contents + ohdr_size, *ptr + ihdr_size, size - ohdr_size);
+      free (*ptr);
+      *ptr = contents;
+    }
+
+  return TRUE;
+}